Methods

Learn to define methods in a class.

Methods

Methods define the behavior of a class's instances. They are written inside the class body like normal functions. Example: class User { String name; void describe() { print(name); } }.

A method can access the class's fields directly. Writing name inside describe refers to the field. this.name means the same.

Methods are called on an instance through a dot: u.describe(). They can take parameters, just like normal functions. When there is no return value, write void.

Method with parameters

Methods can take parameters. Example: void greet(String title) { print('$title $name'); }. This method takes a title when called and prints it together with name.

Call: u.greet('Mr.'). Here 'Mr.' goes into the title parameter; the body combines it with name via $title $name.

Parameterized methods combine the class data with external values. This makes behavior flexible. For a return value, write a type instead of void: String greeting() { return 'Hello $name'; }.

Exercise The describe method

Define a User class with a String name field and a User(this.name) constructor. Add a void describe() method whose body does print(name). Inside main create a User('Ayşe') instance and call u.describe().

Show example solution

class User {
  String name;
  User(this.name);
  void describe() {
    print(name);
  }
}

void main() {
  var u = User('Ayşe');
  u.describe();
}

Test yourself

Match the method parts

void

No return
describe

Method name
()

No parameters
u.describe()

Call
What does name do inside a method?
- Throws
- Reaches the name field of the class
- Declares a new variable
- Counts as a parameter
Show answer

Reaches the name field of the class — name inside a method reaches the class field.

Method definition

class User {
  String name;
  void describe() {
    print(____);
  }
}

Show answer

class User {
  String name;
  void describe() {
    print(name);
  }
}

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